1 /* vsprintf with automatic memory allocation. 2 Copyright (C) 2002-2004, 2007-2020 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3, or (at your option) 7 any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with this program; if not, see <https://www.gnu.org/licenses/>. */ 16 17 #ifndef _VASNPRINTF_H 18 #define _VASNPRINTF_H 19 20 /* Get va_list. */ 21 #include <stdarg.h> 22 23 /* Get size_t. */ 24 #include <stddef.h> 25 26 #ifdef __cplusplus 27 extern "C" { 28 #endif 29 30 /* Write formatted output to a string dynamically allocated with malloc(). 31 You can pass a preallocated buffer for the result in RESULTBUF and its 32 size in *LENGTHP; otherwise you pass RESULTBUF = NULL. 33 If successful, return the address of the string (this may be = RESULTBUF 34 if no dynamic memory allocation was necessary) and set *LENGTHP to the 35 number of resulting bytes, excluding the trailing NUL. Upon error, set 36 errno and return NULL. 37 38 When dynamic memory allocation occurs, the preallocated buffer is left 39 alone (with possibly modified contents). This makes it possible to use 40 a statically allocated or stack-allocated buffer, like this: 41 42 char buf[100]; 43 size_t len = sizeof (buf); 44 char *output = vasnprintf (buf, &len, format, args); 45 if (output == NULL) 46 ... error handling ...; 47 else 48 { 49 ... use the output string ...; 50 if (output != buf) 51 free (output); 52 } 53 */ 54 #if REPLACE_VASNPRINTF 55 # define asnprintf rpl_asnprintf 56 # define vasnprintf rpl_vasnprintf 57 #endif 58 extern char * asnprintf (char *restrict resultbuf, size_t *lengthp, 59 const char *format, ...) 60 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 4)); 61 extern char * vasnprintf (char *restrict resultbuf, size_t *lengthp, 62 const char *format, va_list args) 63 _GL_ATTRIBUTE_FORMAT ((__printf__, 3, 0)); 64 65 #ifdef __cplusplus 66 } 67 #endif 68 69 #endif /* _VASNPRINTF_H */ 70